Annealing machine



April 12 1927. 1,624,204.

T. F. BAILY ANNEALING MACHINE Filed June 6, 1925 y f atto: n m13 Patented Apr. 12, 1927..

THADDEUS F. BAILY,

PATENT OFFICE.

0F ALLIANCE, OHIO.

ANNEALING MACHINE.

Application filed J'une 6,

This invention relates to apparatus for annealing or heat treating sheets, strips and similar material, and the objects of the invention are to provide an annealing furnace in which the material' is continuously passed through the furnace upon or between rolls which are heated by radiation from a suitable heating means, the sheets being heated by direct contact with the heated rolls, rather than by radiation from the heating means.

A. 'further object of the improvement is to provide a furnace of the recuperative type having a. heating chamber at its center and preheating and cooling chambers communieating respectively with the front and rear ends of the heating chamber, rolls being located entirely through the furnace, the rolls in the heating chamber being heated by radiation from the heating elements while the rolls in the preheating chamber are heated by recuperation from the cooling chamber, the rolls in the cooling chamber being cooled by the cooling effect of the incoming cold sheets in the preheating chamber.

The above and other objects may be attained 'by providing an elongated furnace having a heati/ng chamber at its center and pairs of rolls being located closely together through the median line of the furnace, heating means being placed above and below the rolls inthe central or heating chamber, baiiie plates being provided lin the preheating and cooling chambers between each pair of rolls and having ports arranged in staggered relation, the forward endof the preheating chamber communicating, by means of a conduit, with the rear end of the cooling chamber, whereby gases ina be continuously circulated through the urnace in a tortu- 4ons passage in the opposite direction to the travel of the material, and impinged upon the rolls in the cooling and preheatlng chambers and then returned to the opposite fend of the furnace.

A still further object is to provide means whereby certain of the rolls in the preheating and cooling chambers may be heated and cooled respectively by a recuperation of fluid circulated through lsaid rolls ina `closed circuit. a

. An embodiment of the invention is illustrated in the accompanying drawing, in which- Figure`1 is a longitudinal, sectional view through the improved furnace;` and 1925. serialv No. 35,456.

Fig. 2, a detached perspective view of several of the baille plates, showing the staggered ports.

Similar numerals refer to similar parts throughout the drawing. s

This improvement contemplates the use under certain conditions of the recuperative features disclosed in my copending application Serial No. 153, filed January 2, 1925'.

The furnace comprises an elongated tunnel provided at its central portion with a heatlng chamber 1 which may be of larger cross section than the remainder of the tunnel in order to receive heating means such as the electric resistors 2 in the upper and lower portions thereof. The forward end of the tunnel forms a reheating chamber 3, and the rear end of t e tunnel a cooling chamber 4, both of these chambers communicating at theiry inner end-s with the central heating chamber.

A series of pairs of rolls 4, are located through the median line of the entire furnace, each pair of rolls being spaced from the adjacent pairs a distance considerably less than the diameter of'one of the rolls, whereby the material passed through the rolls contacts with an area of rollsurface considerably greater than the distance between the rolls, thus providing for a quick transfer of the roll temperature to the thin sheets or other material passing through the furnace.

The rearmost pair of rolls, .designated at 5, in the cooling chamber are preferably hollow,`ma be formed of cop er or similar material'ofy high 'thermal con uctivity, cold water or other Huid being continuously passed through said rolls as by the pipes 6.A The adjacent pair of rolls 7 in the coolingl chamber, and the rst pair of rolls 8 in the preheating chamber may also be of the same construction and material, fluid of an kind being continuously circulated throng both sets of said rolls in a closed circuit, as by the conduits 9 and 10, a pump or fan 11 being provided therein for maintaining a continuous circulation of the fluid in order to rapidly cool. the rolls 7 and heat the rolls 8 lby recuperation of fluid passing throu h the rolls. The rolls 5` will of course e cooled more rapidly than the rolls 7, ther intention being to bring the sheets substantially to the temperature of the outside atmosphere before they are discharged from the furnace, ,thus preventing any scale forlos mation by Contact of the sheets with the atmosphere while hot.

The intermediate rolls indicated at 4 which extend entirely. through the preheating, heating and cooling chambers between the rolls 8 and 7, are preferably provided with hollow shafts 12 through which cold water y alloy, and the rolls in the preheating and cooling chambers of cast iron or the like, since4 they are not subjected to as intense heat and have a higher thermal conductivity than the heat resisting alloy.V

Battle plates 14 are shown hingedly connected to the upper and lower walls of the preheating and coolin chambers resting against each of the rol ers, alternate baiie plates beingprovided at alternate ends with upper and lower ports 15 and 16 respectively whereby the current of inert or nonoxidizing gas whic is continuously circulated through these chambers, .and through the duct 17 in the heating chamber, in the opposite direction to the travel of the material M, and returned from the preheating to the cooling chamber through the conduit 18, by means of a fan or pump 19, is caused to travel transversely of the furnace between these baffle plates in the directionof the arrows shown in the drawing. f

From the above it Will be obvious that the material is heated by direct contact with the rolls instead of by radiation and the rolls in the heating chamber are heated by radiation from the heating elements 2 to a temperature slightly above that desired in the sheets, while the rolls in the preheating and cooling chambers are heated and cooled by recuperation of the non-oxidizing gases circulated throu h said chambers and impinged pon the ro ls by means of the baffle ates 4let.

It is of course understood that the journals of the rolls will be gas tight, to prevent leakage ofeithe recuperating gas from the furnace; and in order to compensate for normal loss of this gas', means may be provided for adding to the sup ly of gas, such as the pipe 20 entering the urnace from a suitable source of as supply.

Althoug the drawings and above specification disclose the best mode in which I have contemplated embodying my invention I desire to be l'not limited t9 the details of such disclosure, for, in the further practical application of my invention, many 'changes l in frm and construction may be made, as

circumstances require or experience suggests, without departing from the spirit of the invention, within the scope of the appended claims.

I claim: i

1. A furnace including an elongated chamber, a plurality of feeding rolls for passing sheets continuously through the chamber, the distance between adjacent rolls being less than the diameter of each roll and electric heating means above and below the rolls for impinging heat directlyzupon the rolls.

2. A furnace including an elongated chamber, heating means at the center of the chamber, a plurality yof feeding rolls for passing sheets continuously through the chamber, means for circulating gas through the chamber in the opposite direction to the travel of the sheets, and means for impinging the i gas u on the rolls.

furnace including an elongated chamber, heating means at the center of the chamber, a plurality of feeding rolls for passing sheets continuously through the chamber, means for circulating gas through the chamber in a tortuous passage, in the opposite direction to the travel of the sheets and for impinging the gas u on the rolls.

4. In an electric urnace, a pair of rolls for moving material through the furnace` and heatinv elements located above and below the rols and arranged to give maximum heat delivery to the rolls and thence from the rolls to the material.

' 5. In an electric furnace, a plurality 4of rolls for moving material through the furnace, and heating elements located adjacent to the rolls and arranged to give maximum heat delivery to the rolls and thence from the rolls to the material.

6. In an electric furnace, a plurality of rolls for moving material through the furnace and electric means above and below the rolls for delivering maximum heat delivery to the rolls and thence from the rolls to the material. c

7. In an annealing furnace, a plurality of pairs `of rolls for heating and moving material through the furnace, means for circulating a nen-oxidizingl gas through the fur- `nace in the opposite direction to the travel of the sheets, and baiiie plates for directing the gas transversely of the travel of the material and against the rolls to obtain maX- imum heat transfer.

8. In an annealing furnace, a plurality of pairs of3 rolls for heating and moving material through the furnace, means for circulating a gas through the furnace in the opposite direction to the travel ofthe sheets,

and bale plates for directing the Agastransversely` of the travel of the material and against the rolls vto -obtain maximum heat transfer.

9. In an annealing' furnace, a plurality of pairs of rolls for heating and moving inaterial through the furnace, and means for circulating a gas through the furnace in the opposite direction to the travel of the sheets and returning the gas to the opposite end of the furnace in a closed circuit.

ltl. In an annealing'furnace,"a plurality of pairs of rolls for heating and moving material through the furnace, and means for circulating a gasthroughthe furnace in the opposite direction to the travel of the sheets and. returning the gas to the opposite end of the furnace in a closed circuit, the rearmost rollsbeing hollow and means for passing a cooling fluid through said hollow rolls. 11. In an annealing furnace, a plurality of pairs of rolls for heating and moving material through the furnace, and means for circulating a gas tl'irough the furnace in the opposite direction to the travel of the sheets and returning the gas tothe opposite end of the furnace in a closed circuit, certain of the rolls at each end portion of the furnace being hollow and of high thermal conductivity, and means for circulating a Huid through said rolls in a closed circuit for the purpose of recuperation.

l2. In an annealing furnace, a plurality of pairs of rolls for heating and cooling and moving material through the furnace, means at the central portion of the furnace for heating the adjacent rolls, the rollsin the higher temperature zones of the furnace being of heat resisting Aalloy and the rolls in the cooler temperature zones of high thermal conductivity, and means for transferring heat from the' interior of certain of the rolls to the interior of certain other of the rolls.

13. In an annealing furnace, a plurality of vrollsfor moving 'material through lthe furnace and electric heating means above .and below the rolls for impinging heat ldirectly upon the rolls and-thence to the material.

14. In an annealing furnace, an elongated chamber having a central `heating zone, and preheating and cooling z ones communicating with opposite ends thereof, rolls in the chamber for passing sheets therethrough, means for heating the rolls in' the central zone by radiation, and means for heating the rolls in the preheating zone by recuperation from the cooling chamber.

15. An annealing apparatus comprislng i preheating, heated,.and cooling rolls through which the material to be annealed is continuously passed in the order named, the preheating rolls being heated by heat abstracted from the material passing through the cooling rolls, and thecooling rolls being cooled by the incoming cold sheets passing through the preheating rolls.

. 1 6. An annealing apparatus comprising preheating, heated and cooling rolls through which material to be annealed is continuously passed, and means for heating the preheating rollsl by recuperation from the cooling rolls.

17. An annealing apparatus including a series of rollsl through which material to be annealed is continuously passed, means for heating therollsI at the center of thc. appa ratus and means for subjecting the rolls at cach end portion of the apparatus to sub- 'stantially the intlucnce' of the temperature of the rolls at the other end thereof.

18. An annealingv apparatus including af scri'es of rolls through which material to he annealed is continuously passed, means for heating the intermediate rolls, and means for maintaining the rolls in the end portions of the apparatus at substantially the same tcn'iperature.

1t). In an .annealing furnace an elongated chamber having a cent-ral heating zone and preheating' and cooling zones communicating with opposite ends thereof, rolls for moving and heat-ing the material, the rolls in the heating zone heated by electric heat .and the rolls in the 4preheating zone heated by heat abstracted from the cooling zone.

20. An annealing apparatus including a series of heating rolls and a series of cooling rolls, and means for transferring heat absorbed from the cooling rolls to certain of the heating rolls. 21. In an annealing furnace comprising a heating chamber and recuperative chambers,

metal rolls for moving the material through `the furnace, electric heating means for heating the rolls in the heating chamber, and

means for moving a gas through the recupermetal rolls for moving the material through the furnace and for heating and cooling the `material, the heating ofthe preheatin rolls being accomplished by heat abstracte from the heated sheets and the cooling of the cooling rolls being accomplished by means `of the cold moving sheets, the various chambers vmaintained under a non-oxidizing atmosphere.

24C. The method of annealing which. consists in passing the material continuously between a Series of rolls, the rolls .at the center of the series maintained at a temperature above that desired in the sheets and the rolls at the end maintained at substan atmospheric temperature,l abstracting lheat from the 'sheets that have passed their maximum annealing temperature and transferring this`heat to the rolls in Contact with sheets that have not reached their maximum temperature, and maintaining the sheets under treatment in a non-oxidizing atmosphere.

In testimony that I claim the above, I

have hereunto subscribed my name.

THADDEUS F. BAILY. 

